A common question is what is a reasonable hourly rate for drupal programmer or developers. While the range is anywhere between $12 to $110 per hour, it really depends on the complexity of the programming you are asking for.
If you are developing new modules plus custom theme, which is complex in nature the rates can be as high as $100 per hour.
If you are just modifying existing module with minor modification it can be around $40 per hour or less.
The drupal developer will first check the complexity of your requirements before he gives an estimate. Its best to take a fixed price contract rather than working on hourly rate since there is high risk of cost overrun.
Its true that developers in India, China and Subcontinent will charge much less ( starting price $8 per hour) However you will have to check if they are in the position to handle your project. Chances are they would not have handled the complexity and mid way in the project you will find that they cannot complete the project. Go with cheap developers if they can show you the proof of concept and verify that they have done similar project in past, otherwise you will be left in middle of nowhere.
Finally its all demand supply game. Most reputed drupal developers will have their hands full and chances are they may take much longer time to complete your project.
A good approach would be to hire a Drupal consultant to see if existing modules can be used to build the site you want and you can get minor modifications and theme built as per your requirements. Drupal is not difficult to learn, with 2-3 days effort you can get a good handle of what is what in Drupal.